Just like in his last film, the CGI-rich albeit hollow-to-the-core sequel “TRON: Legacy,” filmmaker Joseph Kosinski captures an exciting setting in his second movie “Oblivion.” In this Tom Cruise-vehicle, Kosinski’s idea of a futuristic, post-war Earth is vast and dreary. High-tech drones blaze through the sky with purpose. The planet is lifeless, but Kosinski’s vision isn’t. It’s not until characters actually speak and a plot is brought to the forefront when “Oblivion” becomes just another dull sci-fi genre flash in the pan.

Cruise, who is no stranger to substantial science fiction like “Minority Report” and “War of the Worlds,” tries his best to keep the drama high as the director maintains the fascinating world around him. He stars as Jack Harper, a security expert whose mission is to monitor drones on Earth. Along with his partner Victoria (Andrea Riseborough), the duo is only two weeks away from clocking out and joining their fellow humans who have been transported to another planet after a nuclear war ravaged the world uninhabitable. Hanging out in the shadows of Earth are aliens called “scavs” who are hellbent on attacking machines built to harvest the Earth’s remaining ocean water.

If that read like a jumbled up narrative, that’s because it is. In fact, we haven’t even started to explain why Jack is seeing a mysterious woman (Olga Kurylenko) in his dreams or why an annoyingly southern-accented Melissa Leo is giving him the runaround via video transmission or why the heck Morgan Freeman shows up wearing shades and smoking a cigar. Besides not wanting to ruin some of the surprises “Oblivion” has in store, we also don’t want to dilute the synopsis as much as screenwriters here do with the script. “Oblivion” is a sprawling mess filled with big, muddy ideas. It’s a perfect example of a sci-fi movie that over-thinks its mythology and ends up forcing the viewer right out of the story.

It’s also not very mindful of other recent sci-fi movies that share some of its major twists. Sure, there are plenty of movies out there that cover the same themes and a few of the scenarios seen in “Oblivion,” but it boggles the mind to understand how a couple of them didn’t set off the copycat alarms. And no, we’re not talking about Cruise reliving his fighter-pilot days in “Top Gun.” Here he’s impressive behind the controls of a high-speed spacecraft. Too bad the year is 2077 and not 1986.

Off his Oscar win for the gorgeously shot “Life of Pi,” the work of cinematographer Claudio Miranda is easily the film’s forte. From a shootout inside an abandoned library to the eye-melting landscapes and skyscapes, the images in “Oblivion” coincide with its $120-million price tag. Producers should’ve skimped on a few CGI drones, however, and transferred some of those funds to someone who could’ve tightened up the screenplay with a vise.